Process for debittering peanut hearts

ABSTRACT

The present invention discloses methods for preparing a processed peanut product containing high levels of peanut hearts material, with the peanut heart material being substantially stripped of bitter taste so as to provide debittered peanut hearts of comparable taste to actual peanuts or as being flavorless without adversely affecting the taste of a foodstuff end product. The processed product includes whole or fragmented peanut hearts and peanut heart powder processed using alkaline wash, neutralization, and drying for inactivating enzymes and removing bitter flavoring components. The peanut heart materials are debittered by adjusting the pH to about 8 to about 12 with an alkali material (e.g., sodium hydroxide) to solubilize the protein content and release the bitter flavor compounds making it possible to separate such compounds by ultrafiltration. The alkali treated peanut heart material is neutralized with an acidic aqueous solution.

FIELD OF THE INVENTION

[0001] The present invention relates to utilization of peanut hearts orthe germ of the peanut in the preparation of peanut products in largevolume. The debittered peanut heart compositions of this invention areespecially suitable for use in, for example, peanut butters, sauces,grits, candies, energy bars, and the like. Peanut hearts constitute aportion of the peanut that is generally not acceptable for humanconsumption at high levels due to extremely bitter taste. The presentinvention provides processes for producing debittered peanut heartmaterials having taste comparable to actual peanuts for incorporationinto end products at relative high levels for significant cost savings.These processes allow for debittering peanuts, especially peanut hearts,both as whole or fragmented pieces or as debittered peanut heart powderproduced using described water-based processes of the invention.

BACKGROUND OF THE INVENTION

[0002] Peanuts constitute an important foodstuff and are often employedas a material ingredient in end products for their substantial foodvalue (e.g., substantial protein and oil content). However, peanuthearts or germs have an extremely bitter taste. Thus, peanut heartmaterial is normally discarded in commercial food processing so as tolimit or eliminate significant levels of peanut heart materials in endproducts because of consumers preferences for non-bitter food products.Moreover, a bitter tasting substance can often be sensed even when it ispresent in extremely small amounts as compared to other materialspresent in the end product. Accordingly, the presence of an unpleasantbitter taste is of serious concern in the food industry, and further maybe problematic in other industries such as the medicinal andpharmaceutical industries. The desire for improved palatability hasprompted the development of numerous approaches for inhibiting, masking,or otherwise reducing bitterness so as to not affect the overall flavorin the resulting foodstuff. Such problems have been recognized for manyyears.

[0003] An example of previously employed methods to purify organicmaterials is shown in U.S. Pat. No. 4,477,480 to Seidel et al. for“Method Of Preparing A Clean Flavored Cereal Starch” issued Oct. 16,1984, in which starch is treated with an alkali to remove objectionableflavor components. In U.S. Pat. No. 4,761,186 to Schara et al. for“Method Of Purifying Starches And Products Produced Therefrom” issuedAug. 2, 1988, ultrafiltration is used to purify starch. In both cases,flavor components are removed from the starch, in the '480 patent bysolubilizing the flavor components so that they can be washed out of therelatively insoluble starch. In the '186 patent, ultrafiltration wasused to remove the flavor components as permeate while the insolublestarch remained in an aqueous slurry.

[0004] U.S. Pat. No. 6,197,356 B1 to Girsh for “Process For PreparingHypoallergenic Foods” issued Mar. 6, 2001, provides for a method forrendering common allergenic foods, including peanuts, hypoallergenic byheat treatment with a super critical fluid or gas (e.g., super criticalcarbon dioxide or liquid nitrogen). U.S. Pat. No. 5,785,984 to Kuriharaet al. for “Taste-Modifying Method And Bitterness-Decreasing Method”issued Jul. 28, 1998, provides for a protein-lipid complex which, whenadded to food (including peanuts) or other compositions, decreasesbitterness. The complex appears to mask the bitterness rather thaneliminate it from the product. U.S. Pat. No. 5,766,622 to Nelson for“Inhibiting Undesirable Taste In Oral Compositions” issued Jun. 16,1998, provides for a method of inhibiting an undesirable taste in food(including peanuts) and other compositions by the addition of aphosphorylated amino acid. U.S. Pat. No. 5,756,543 to Katsuragi et al.for “Bitterness-Relieving Agent” issued May 26, 1998, provides for abitterness-relieving agent which can be added to food (includingpeanuts) and other compositions. The agent is an ester of a mono- ordiglyceride with a polycarboxylic acid or a salt thereof. U.S. Pat. No.4,211,694 to Youngquist for “Deflavoring Vegetable Seed Materials”issued Jul. 8, 1980, provides for a method for deflavoring vegetableseed materials (including peanuts) using a ternary single-phase solutionof water, electrolyte, and carbohydrate. The solution has a wateractivity of less than about 0.9. The process can be carried out bysuspending the seed material in the solution and mixing for about 10minutes to about 24 hours at a temperature of about 0 to about 120° C.U.S. Pat. No. 3,998,800 to Youngquist for “Deflavoring Oleaginous SeedProtein Materials” issued Dec. 21, 1976, provides for a method fordeflavoring oleaginous seed materials (including peanuts) using a singlephase composition containing a non-polar oxygen-containing organicsolvent (e.g., alcohol) and water. U.S. Pat. No. 3,947,599 to Mitchell,Jr. for “Process For Making Flavorless Food Extenders Derived FromPeanuts, And A Method Of Recovering Peanut Oil” issued Mar. 30, 1976,provides for a method for preparing flavorless peanut flakes. Thismethod comprises coarsely grinding blanched unroasted peanuts, mixingwith water, forming a suspension of finely divided peanut particles andemulsified oil, drying the emulsion-suspension to form flakes,extracting oil from the flakes using an organic solvent (e.g.,hydrocarbon), and removing residual solvent from the flakes.

[0005] As can be seen from the above summary, the problem of debitteringpeanut hearts has not been adequately addressed in the food processingarts. Moreover, none of the prior art specifically provides fordebittering processes that take advantage of a water-based process forprocessing peanut hearts for human consumption. Inasmuch as peanuthearts generally are associated with an extremely bitter flavor, muchmore so than many other foodstuffs, it is not readily apparent that anyknown prior art processes could produce debittered peanut hearts.

SUMMARY OF THE INVENTION

[0006] The present invention provides methods for incorporating peanuthearts into food products for human consumption, even at high levels inwhich the debittered peanut hearts are of comparable taste to actualpeanuts or provided as flavorless peanut hearts so as to not adverselyaffect the taste of the food product. Both whole debittered peanuthearts and debittered peanut heart powder may be produced using awater-based process of the present invention. Thus, the use of organicsolvents is avoided.

[0007] The present invention discloses a method of obtaining whole orfragmented peanut heart material substantially free of bitter taste, themethod including the steps of:

[0008] (1) washing whole or fragmented peanut heart material with anaqueous alkaline solution;

[0009] (2) repeating step (1) until the whole or fragmented peanut heartmaterial is substantially free of bitter taste;

[0010] (3) neutralizing the alkaline-washed whole or fragmented peanutheart material with an aqueous acidic solution; and

[0011] (4) drying the peanut hearts from step (4) to obtain the whole orfragmented peanut heart material substantially free of bitter taste.Preferably, the whole or fragmented peanut heart material is blanched inhot or boiling water prior to the alkaline wash treatment. If desired,the whole or fragmented peanut heart material substantially free ofbitter taste may be roasted prior to use.

[0012] In addition, the present invention further discloses a method forproducing peanut heart powder substantially free of bitter taste, themethod including the steps of:

[0013] (1) grinding peanut hearts to form an aqueous slurry containingpeanut heart material;

[0014] (2) washing the aqueous slurry with an aqueous alkaline solution;

[0015] (3) filtering the aqueous slurry before or after step (2) toremove large particles of the peanut heart material;

[0016] (4) treating the washed and filtered aqueous slurry with anultrafiltration process to remove bitter flavor components;

[0017] (5) repeating steps (2) and (4) until the peanut heart materialin the aqueous slurry is substantially free of bitter taste;

[0018] (6) neutralizing the aqueous slurry from step (5) with an aqueousacidic solution; and

[0019] (7) drying the neutralized aqueous solution from step (6) toobtain peanut heart powder substantially free of bitter taste.Preferably, the peanut heart material is blanched in hot or boilingwater prior to the alkaline wash treatment. If desired, the peanut heartpowder substantially free of bitter taste may be roasted prior to use.

[0020] The debittered peanut heart material obtained from the processesof the invention allow the incorporation of high levels of peanut heartmaterial in a wide range of foods without the bitterness normallyassociated with peanut hearts.

[0021] In one aspect, the invention is a method of debittering peanutheart materials including adjusting the pH to about 8 to about 12(preferably about 10 to about 11) with an alkali material (e.g., sodiumhydroxide) to solubilize the protein content and releasing the bitterflavor compounds, making it possible to separate and remove the bitterflavor components associated with the bitterness characteristic and,thereby, produce peanut heart material that is substantially free ofbitter taste. For purposes of this invention, removal of essentially allof the bitter flavoring compounds or being substantially stripped orfree of bitter taste is achieved when the bitterness has been reduced toan acceptable level or, more preferably, has been essentiallyeliminated.

[0022] Both whole peanut heart material and powered peanut heartmaterial can be produced by the methods of the present invention. Forwhole peanut heart material, whole or fragmented peanut heart materialis optionally blanched in hot (greater than about 90° C.) or,preferably, boiling water. The whole or fragmented peanut heart material(blanched or unblanched) is washed with a basic aqueous solution untilit is substantially free of bitter taste. After neutralizing with anacidic aqueous solution, the whole peanut material is dried to obtainthe debittered peanut heart material. If desired, this material can beroasted.

[0023] For powdered peanut heart material, whole or fragmented peanutheart material is optionally blanched in hot (greater than about 90° C.)or, preferably, boiling water. The whole or fragmented peanut heartmaterial (blanched or unblanched) is ground to form an aqueous slurry(e.g., wet milling). The slurry is pH-adjusted with an aqueous alkalinesolution and then subjected to ultrafiltration using a membrane capableof retaining substantially all of the protein content while removingbitter flavoring components as permeate. The aqueous slurry is filteredto remove large particles (e.g., insoluble fibers) either before orafter the pH of the slurry is adjusted. The permeate containing bitterflavor components and water is exposed to a reverse osmosis membrane todewater the permeate; the separated water, along with recycledretentate, can be recycled to treat fresh pH-adjusted peanut materials.The peanut heart materials are batch, semi-continuously, or continuouslyprocessed wherein a pH-adjusted aqueous slurry is exposed to anultrafiltration membrane and/or reverse osmosis membrane, the permeateis separated for recovery or removal of the bitter flavor components,and the retentate is recycled to treat fresh pH-adjusted peanutmaterials. Water is added periodically or continuously to replace thewater lost to the permeate and to adjust the concentration of peanutmaterials in the combined stream to a predetermined level. The process(i.e., alkaline washing followed by ultrafiltration) is continued untilessentially all of the bitter flavoring compounds have been removed andthe peanut heart material is substantially free of bitter taste. Afterneutralizing with an acidic aqueous solution, the resulting material isdried to obtain the debittered peanut heart material. If desired, thismaterial can be roasted.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024]FIG. 1 is a block diagram of one process employing the inventionin which whole peanut hearts are optionally blanched in boiling waterfollowed by successive washings (e.g., about 2-6 washings) in an aqueousalkaline solution (e.g., 1N NaOH) at about 25 to about 65° C. Thealkaline-washed peanut hearts are then washed with a neutralizingaqueous solution (e.g., 0.5N HCl) to a pH of about 7 and then dried toobtain whole or fragmented peanut hearts which are substantially free ofbitterness.

[0025]FIG. 2 is a block diagram of another process employing theinvention in which optionally blanched peanut hearts are ground to forman aqueous slurry and then filtered to remove large particles (althoughnot shown, this filtration step can be carried out after the pH of theslurry is adjusted). The resulting suspension is treated with an aqueousalkali solution and then ultrafiltered/diafiltered multiple times toremove flavor components associated with bitterness. The resultingproduct is then neutralized and dried to obtain a peanut heart powderwhich is substantially free of bitterness.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] The present invention provides peanut compositions, andparticularly peanut heart compositions, and methods of preparing andusing peanut hearts that offer improved utilization of such foodmaterial for human consumption at high levels. The peanut compositions,and especially the peanut heart compositions, of the present inventionhave been stripped of bitter taste and have a pleasant peanut flavor.The starting material of the present invention comprise peanuts thatgenerally include peanut hearts or the germ of the peanut processed foruse in a wide variety of food products. The debittered peanut heartproducts are provided as processed peanut hearts, fragments, or groundpeanut heart powder material substantially stripped of bitter taste, andhaving a pleasant peanut flavor.

[0027] Debittering may be accomplished with alkali treatment due to thesolubility of phenolic compounds at an alkaline or basic pH. Thisconcept as applied to peanut heart materials provides a number ofembodiments in accordance with the invention for alkaline washing andpH-adjustment for the release and separation of bitter flavor compoundsthrough alkaline washing or alkaline washing combined withultrafiltration (with or without diafiltration) and the like asprocesses for debittering peanut hearts. The processed product includeswhole or fragmented peanut hearts and peanut heart powder processedusing blanching (an optional step), alkaline wash neutralization, anddrying for inactivating enzymes and removing bitter flavoringcomponents. The peanut heart materials are debittered by adjusting thepH to about 8 to about 12 (preferably about 10 to about 11) with analkali material such as sodium, potassium, calcium, or magnesiumhydroxides to solubilize the protein content and release the bitterflavor compounds making it possible to separate such compounds from thedesired peanut heart material. The alkali treated peanut heart materialis neutralized with an acidic water solution.

[0028] A first process (see FIG. 1) produces a whole or fragmenteddebittered peanut heart. This process involves optionally blanchingpeanut hearts in hot (greater than about 90° C.) or, preferably, boilingwater. The blanched or unblanched peanut heart material is then treatedby successive washings (e.g., 2-6 washings) in an alkaline solution atabout 25 to about 65° C. After the alkaline washing is complete, thepeanut heart material is neutralized with an appropriate aqueous acidsolution (e.g., 0.5N HCl) wash to a pH of about 5 to about 7.5, andpreferably to a pH of about 7. Suitable aqueous acid solutions include,for example, aqueous HCl, aqueous citric acid, aqueous phosphoric acid,and the like. The peanut heart material may then be dried in aconventional oven (e.g., conduction, convection oven, fluid bed typedryer, freeze drier, spray dryer, extrusion dryer, or the like). Ifdesired, this material can be roasted.

[0029] A second process (see FIG. 2) produces a debittered peanut heartpowder. This process involves optionally blanching the peanut heartmaterial in hot (greater than about 90° C.) or, preferably, boilingwater. The blanched or unblanched peanut heart material is then groundinto a slurry and filtered to remove large particulates (i.e.,particles, especially insoluble fibers, having an average diameter orlength of greater than about 100 microns). Although not shown in thefigure, this filtration step can be carried out after the pH of theslurry is adjusted. The resulting aqueous slurry suspension is thenalkalized and subject to ultrafiltration (with or without diafiltration)multiple times. The resulting peanut product is then neutralized usingan aqueous acid solution (e.g., 0.5N HCl) to a pH of about 5 to about7.5, and preferably to a pH of about 7. Suitable aqueous acid solutionsinclude, for example, aqueous HCl, aqueous citric acid, aqueousphosphoric acid, and the like. The peanut heart powder end product isthen dried in a conventional oven (e.g., conduction oven, convectionoven, fluid bed type dryer, freeze drier, spray drier, extrusion drier,or the like). If desired, this material can be roasted.

[0030] Many food producers utilize peanuts and peanut products in largevolume. Products include peanut butters, sauces, grits, candies, energybars, roasted peanuts, and the like. Peanut hearts constitute a portionof the peanut that is normally not consumed in high levels due to itsextremely bitter taste. The process of debittering peanut hearts makesthem comparable in taste to actual peanuts which can be incorporatedinto different products and at higher levels in such foodstuff endproducts. In additions, significant cost savings can be realized bybeing able to process and incorporate the peanut heart material intoproducts for human consumption.

[0031] With reference to FIG. 1, a first embodiment is illustrated forthe preparation of fragmented or whole debittered peanut hearts. Wholepeanut hearts are provided and are optionally blanched in hot (greaterthan about 90° C.) or, preferably, boiling water (e.g., forapproximately 3 minutes or more) and then rinsed with cold water. Theoptional blanching may be repeated multiple times until the blanchedpeanut hearts are sufficiently soft to allow for diffusion of the laterperformed alkali washing. The purpose of the optional blanching step isto inactivate enzymes and also to soften the peanut tissue such thatsubsequent alkali washing provided in connection with this process willbe effective. The softening of the peanut hearts facilitates thediffusion of the alkaline solution wash into the peanut heart material.Thus, it is generally preferred that one or more blanching steps beincluded in the present process. The alkaline wash step may be repeatedmultiple times (e.g., 2-6 times as shown in FIG. 1), such that theblanched or unblanched peanut hearts are then resuspended in an aqueousalkali solution (e.g., 1N NaOH) to a pH of about 8 to about 12(preferably about 10 to about 11). The alkalized peanut heart materialmay then be mixed (e.g., for about 45 minutes or more) at about 25 toabout 65° C., and preferably at about 50° C. The method of debitteringthe peanut heart material thus includes adjusting the pH with an alkalisuch as sodium, potassium, calcium, or magnesium hydroxides tosolubilize the protein content and release the bitter flavor compounds,making it possible to separate the compounds. The one or more washingsteps using aqueous alkaline are generally carried out at a temperatureof about 25 to about 65° C.

[0032] After the end of the alkaline washing, the alkaline solution maybe removed using conventional techniques (e.g., filtration, decantation,centrifugication, and the like). The peanut heart material can then berinsed several times (e.g., 1-6 times or more) with an aqueous acidicsolution. This neutralizing step, including washing and rinsing, may berepeated multiple times with a aqueous acidic solution (e.g., 0.5N HCl)to a pH of about 5 to about 7.5, and preferably about 7; generally theneutralized step is repeated about 1-6 times or more as needed. Thewhole peanut heart material is then dried using conventional techniques,including conduction or convection ovens, a fluid bed type dryer, freezedryer, spray dryer, extrusion dryer, and the like. If desired, thismaterial can be roasted using conventional techniques prior to use.

[0033] With reference to FIG. 2, a second embodiment is illustrated forthe preparation of debittered peanut heart powder using anultrafiltration (UF) (with or without diafiltration) step to assist inthe removal of the bitter flavor. The whole peanut hearts are optionallyblanched in hot (greater than about 90° C.) or, preferably, boilingwater and ground into an aqueous slurry. Generally blanching ispreferred as it has the same effect as described above in the discussionof FIG. 1. The blanched or unblanched peanut heart material may befinely ground in water using conventional techniques (e.g., foodgrinder, food processor, wet milling equipment, or the like) to obtain aslurry with a solids content of about 5 to about 50 percent andpreferably of about 10 to about 25 percent. Generally, the averageparticle size of the ground peanut heart material is about 1 to about100 microns, preferably about 10 to about 80 microns, and morepreferably about 50 to about 75 microns.

[0034] The slurry is filtered to remove relatively large insolubleparticulates (generally particles greater than about 100 microns indiameter or length), including, for example, insoluble fiber. Thisinitial filtering step may be performed, for example, with a cheesecloth, a coarse membrane filter, strainer, or the like. The resultingaqueous slurry may then be alkalized with hydroxides as discussed above(e.g., using a sodium hydroxide NaOH) to a basic pH of about 8 to about12 (preferably about 10 to about 11). Alternatively, the pH of theslurry may be adjusted prior to removal of the relatively largeinsoluble particulates by filtration. Adjusting the pH to the desiredrange with an alkali allows solubilization of the protein content andrelease of the bitter flavor compounds, making it possible to use anultrafiltration membrane to separate the bitter flavor components.Suitable ultrafiltration membranes generally have a molecular weightcutoff (MWCO) in the range of about 10 K to about 50 K. Theultrafiltration can be used alone or in combination with diafiltration.Preferably, ultrafiltration combined with diafiltration is employed.

[0035] The suspension is then successively treated multiple times (e.g.,two or more times) with the alkali treatment and ultrafiltration (withor without diafiltration). The ultrafiltration uses a membrane capableof retaining substantially all of the protein content while removingbitter flavoring components as permeate. The permeate containing bitterflavor components and water can be treated with a reverse osmosismembrane to dewater the permeate and the separated water can be recycledwith or without recycled retentate and fresh pH-adjusted peanutmaterials. A portion of the retentate can be continually removed and thedebittered peanut heart materials recovered. The peanut heart materialscan be processed in batch, semi-continuous, or continuous mode wherein apH-adjusted aqueous slurry is subject to ultrafiltration, the permeateis separated for removal and/or recovery of the bitter components, andthe retentate (free of bitter flavor components) is recycled to treatfresh pH-adjusted peanut materials. Water can be added periodically orcontinuously to replace the water lost to the permeate and to adjust theconcentration of peanut materials in the combined stream to apredetermined level. The process is continued until essentially all ofthe bitter flavoring compounds have been removed. When ultrafiltrationis complete, the debittered slurry is treated with an aqueous acidicsolution (e.g., 0.5N HCl) to adjust the pH to about 5 to about 7.5, andpreferably to about 7. The neutralized peanut slurry may then be driedusing conventional techniques (e.g., conduction or convection ovens, afluid bed type dryer, thin-film dryer, freeze dryer, spray dryer,extrusion dryer, and the like) to provide a dry debittered peanutpowder. This debittered peanut powder may be added directly to thedesired food product or may be hydrated (e.g., about 10 percent solids)before being added. If desired, this material can be roasted prior touse using conventional techniques.

[0036] The present invention provides improved usability of peanut heartmaterial in peanut products for human consumption since the debitteredpeanut hearts produced have essentially no bitter taste and a pleasantpeanut flavor. The following examples are provided to illustrate theinvention and not to limit it. Unless otherwise indicated, allpercentages and ratios are by weight. One skilled in the art willunderstand that suitable operating parameters will be determined byexperience with the materials being separated.

EXAMPLE 1

[0037] Peanut hearts (300 g) were blanched in boiling water (1 liter tapwater) for 2-10 minutes. The blanched hearts were rinsed with coldwater. Blanching was repeated twice. Blanched hearts were thenresuspended in 600 g fresh water. The suspension was alkalized to pH 11with 1N NaOH, and then mixed in a jacketed beaker at about 50° C. forabout 30-45 minutes. At the end of the wash, the hearts were rinsed withfresh water. The washing and rinsing was repeated 4 times. The peanuthearts were then resuspended in water, neutralized to pH 7 with 0.5NHCl, and mixed for five minutes. The neutralizing water was decanted andthe hearts were dried overnight in a convection oven at 50° C. Drydebittered peanut hearts were sensory evaluated by several colleagues.The debittered samples were characterized as bland with no bitter tastedetected.

EXAMPLE 2

[0038] Blanched peanut hearts were suspended in water and thenthoroughly ground into a slurry (about 10 percent solids) in a foodprocessor. The slurry was then filtered through a cheese cloth to removelarge particulate (large insoluble fibers). The filtrate suspension wasthen adjusted to pH 11 with 1N NaOH, and ultrafiltered through a hollowfiber membrane with 30 K MWCO. The alkaline washing and ultrafiltrationwas repeated five times. The product was neutralized to a pH of about 7with 0.5N HCl. The slurry was freeze dried. Dry debittered peanut heartpowder was hydrated in water at about 10 percent solids; no bitter tastewas detected in the end product.

EXAMPLE 3

[0039] Unblanched peanut hearts (500 g) were mixed with water (1000 g)at about 50° C. The pH of the mixture was adjusted to about 10 using 1NNaOH and then stirred at about 50° C. for about 45 minutes; additionalbase was added as needed to maintain the pH at about 10. The peanuthearts were washed with fresh water and drained. The alkaline washtreatment was repeated for a total of three wash cycles. Aftercompletion of the final alkaline wash, the peanut hearts were suspendedin fresh water, neutralized to pH 7 with 0.5M HCl, and mixed for about 5minutes. After decanting the water layer, the peanut hearts were driedin a fluid bed drier (Glatt Agglomerator) at about 80° C. for about 100minutes to a moisture content of about 2 to about 5 percent. The driedpeanut hearts (100 g at a time) were then dry roasted in a benchtopNeuhaus Neotec roaster at about 200° C. for about 370 seconds. The dryroasted debittered peanut hearts were characterized by a taste panel asbeing peanutty in flavor with only a very slight bitter aftertaste.

What is claimed is:
 1. A method of obtaining whole or fragmented peanutheart material substantially free of bitter taste, the method includingthe steps of: (1) washing whole or fragmented peanut heart material withan aqueous alkaline solution; (2) repeating step (1) until the whole orfragmented peanut heart material is substantially free of bitter taste;(3) neutralizing the alkaline-washed whole or fragmented peanut heartmaterial with an aqueous acidic solution; and (4) drying the peanuthearts from step (4) to obtain the whole or fragmented peanut heartmaterial substantially free of bitter taste.
 2. The method as recited inclaim 1, wherein the whole or fragmented peanut heart material isblanched in hot or boiling water prior to step (1).
 3. The method asrecited in claim 1, wherein the aqueous alkaline solution containssodium hydroxide, potassium hydroxide, calcium hydroxide, magnesiumhydroxide, or mixtures thereof.
 4. The method as recited in claim 1,wherein step (2) is repeated about 4 to about 6 times.
 5. The method asrecited in claim 1, wherein the aqueous alkaline solution containssodium hydroxide and wherein step (2) is carried out at about 25 toabout 65° C.
 6. The method as recited in claim 1, wherein sufficientaqueous alkaline solution is used in step (2) to obtain a pH of about 8to about
 12. 7. The method as recited in claim 5, wherein sufficientaqueous alkaline solution is used in step (2) to obtain a pH of about 8to about
 12. 8. The method as recited in claim 1, wherein neutralizingthe alkaline-washed whole or fragmented peanut heart material isneutralized with an acidic aqueous solution to a pH of about 5 to about7.5.
 9. The method as recited in claim 7, wherein neutralizing thealkaline-washed whole or fragmented peanut heart material is neutralizedwith an acidic aqueous solution to a pH of about 5 to about 7.5.
 10. Themethod as recited in claim 1, wherein the whole or fragmented peanutheart material substantially free of bitter taste is roasted.
 11. Themethod as recited in claim 2, wherein the whole or fragmented peanutheart material substantially free of bitter taste is roasted.
 12. Apeanut heart material substantially stripped of bitter taste, whereinthe peanut heart material is prepared by a method comprising: (1)washing whole or fragmented peanut heart material with an aqueousalkaline solution; (2) repeating step (1) until the whole or fragmentedpeanut heart material is substantially free of bitter taste; (3)neutralizing the alkaline-washed whole or fragmented peanut heartmaterial with an aqueous acidic solution; and (4) drying the peanuthearts from step (4) to obtain the whole or fragmented peanut heartmaterial substantially free of bitter taste.
 13. The peanut heartmaterial as recited in claim 12, wherein the whole or fragmented peanutheart material is blanched in hot or boiling water prior to step (1).14. A method for producing peanut heart powder substantially free ofbitter taste, the method including the steps of: (1) grinding peanuthearts to form an aqueous slurry containing peanut heart material; (2)washing the aqueous slurry with an aqueous alkaline solution; (3)filtering the aqueous slurry before or after step (2) to remove largeparticles of the peanut heart material; (4) treating the washed andfiltered aqueous slurry with an ultrafiltration process to remove bitterflavor components; (5) repeating steps (2) and (4) until the peanutheart material in the aqueous slurry is substantially free of bittertaste; (6) neutralizing the aqueous slurry from step (5) with an aqueousacidic solution; and (7) drying the neutralized aqueous solution fromstep (6) to obtain peanut heart powder substantially free of bittertaste.
 15. The method as recited in claim 14, wherein the peanut heartmaterial is blanched in hot or boiling water prior to the alkaline washtreatment.
 16. The method as recited in claim 14, wherein theultrafiltration process includes diafiltration.
 17. The method asrecited in claim 14, wherein the aqueous alkaline solution containssodium hydroxide, potassium hydroxide, calcium hydroxide, magnesiumhydroxide, or mixtures thereof.
 18. The method as recited in claim 16,wherein the aqueous alkaline solution contains sodium hydroxide,potassium hydroxide, calcium hydroxide, magnesium hydroxide, or mixturesthereof.
 19. The method as recited in claim 14, wherein steps (2) and(4) are repeated about 4 to about 6 times.
 20. The method as recited inclaim 15, wherein steps (2) and (4) are repeated about 4 to about 6times.
 21. The method as recited in claim 16, wherein steps (2) and (5)are repeated about 4 to about 6 times.
 22. The method as recited inclaim 14, wherein the aqueous alkaline solution contains sodiumhydroxide and wherein step (2) is carried out at about 25 to about 65 °C.
 23. The method as recited in claim 16, wherein the aqueous alkalinesolution contains sodium hydroxide and wherein step (2) is carried outat about 25 to about 65 ° C.
 24. The method as recited in claim 14,wherein sufficient aqueous alkaline solution is used in step (2) toobtain a pH of about 8 to about
 12. 25. The method as recited in claim15, wherein sufficient aqueous alkaline solution is used in step (2) toobtain a pH of about 8 to about
 12. 26. The method as recited in claim16, wherein sufficient aqueous alkaline solution is used in step (2) toobtain a pH of about 8 to about
 12. 27. The method as recited in claim24, wherein the aqueous slurry from step (5) is neutralized with anacidic aqueous solution to a pH of about 5 to about 7.5.
 28. The methodas recited in claim 25, wherein the aqueous slurry from step (5) isneutralized with an acidic aqueous solution to a pH of about 5 to about7.5.
 29. The method as recited in claim 26, wherein the aqueous slurryfrom step (5) is neutralized with an acidic aqueous solution to a pH ofabout 5 to about 7.5.
 30. The method as recited in claim 14, wherein theultrafiltration is carried out using a membrane with a molecular weightcutoff in the range of about 10 K to about 50 K.
 31. The method asrecited in claim 15, wherein the ultrafiltration is carried out using amembrane with a molecular weight cutoff in the range of about 10 K toabout 50 K.
 32. The method as recited in claim 16, wherein theultrafiltration is carried out using a membrane with a molecular weightcutoff in the range of about 10 K to about 50 K.
 33. The method asrecited in claim 14, wherein the peanut heart powder substantially freeof bitter taste is roasted.
 34. The method as recited in claim 15,wherein the peanut heart powder substantially free of bitter taste isroasted.
 35. The method as recited in claim 16, wherein the peanut heartpowder substantially free of bitter taste is roasted.
 36. A peanut heartpowder substantially stripped of bitter taste, wherein the peanut heartpowder is prepared by a method comprising: (1) grinding peanut hearts toform an aqueous slurry containing peanut heart material; (2) washing theaqueous slurry with an aqueous alkaline solution; (3) filtering theaqueous slurry before or after step (2) to remove large particles of thepeanut heart material; (4) treating the washed and filtered aqueousslurry with an ultrafiltration process to remove bitter flavorcomponents; (5) repeating steps (2) and (4) until the peanut heartmaterial in the aqueous slurry is substantially free of bitter taste;(6) neutralizing the aqueous slurry from step (5) with an aqueous acidicsolution; and (7) drying the neutralized aqueous solution from step (6)to obtain peanut heart powder substantially free of bitter taste. 37.The peanut heart powder as recited in claim 36, wherein the peanut heartmaterial is blanched in hot or boiling water prior to the alkaline washtreatment.
 38. The peanut heart powder as recited in claim 36, whereinthe ultrafiltration process includes diafiltration.